Wafer processing apparatus and method of manufacturing semiconductor device using the same

ABSTRACT

A wafer processing apparatus includes: a laser apparatus configured to generate a laser beam; a focusing lens optical system configured to focus the laser beam on an inside of a wafer; an arbitrary wave generator configured to supply driving power to the laser apparatus; and a controller configured to control the arbitrary wave generator, wherein the laser beam includes a plurality of pulses sequentially emitted from the laser apparatus, and wherein each of the plurality of pulses is a non-Gaussian pulse, and a full width at half maximum (FWHM) of each of the plurality of pulses ranges from 1 ps to 500 ns.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2020-0057815, filed on May 14, 2020, in the Korean IntellectualProperty Office, the disclosure of which is incorporated by referenceherein in its entirety.

BACKGROUND

The inventive concept relates to a wafer processing apparatus and amethod of manufacturing a semiconductor device using the waferprocessing apparatus, and more particularly, to a wafer processingapparatus configured to perform a stealth dicing process and a method ofmanufacturing a semiconductor device using the wafer processingapparatus.

A laser processing process refers to a process of processing a shape orphysical property of the surface of a workpiece by scanning a laser beamon the surface of the workpiece. The laser processing process includes,for example, a patterning process of forming a pattern on the surface ofthe workpiece, a process of modifying the physical properties of theworkpiece, such as wafer annealing, a molding process of changing theshape of the workpiece through heat melting, a cutting process ofcutting the workpiece into a plurality of units through heat melting,etc.

The cutting process using a laser beam according to the related art cutsthe workpiece by irradiating the workpiece with laser light of awavelength band having a high absorption rate and heating and meltingthe workpiece. When a wafer is melted and cut, there is a problem inthat not only a cutting region but also a surrounding region is meltedand a part of a semiconductor device formed on the wafer is damaged.

To solve this problem, a stealth dicing technology of focusing the laserbeam on an inside of the workpiece and inducing an internal breakage isused.

SUMMARY

The inventive concept provides a wafer processing apparatus havingenhanced reliability and a method of manufacturing a semiconductordevice using the wafer processing apparatus.

Objects of the inventive concept are not limited to the aforesaid, andother objects not described herein will be clearly understood by thoseof ordinary skill in the art from descriptions below.

According to another aspect of the inventive concept, there is provideda wafer processing apparatus. The wafer processing apparatus mayinclude: a laser apparatus configured to generate a laser beam; afocusing lens optical system configured to focus the laser beam on aninside of a wafer; an arbitrary wave generator configured to supplydriving power to the laser apparatus; and a controller configured tocontrol the arbitrary wave generator, wherein the laser beam includes aplurality of pulses sequentially emitted from the laser apparatus, andwherein each of the plurality of pulses is a non-Gaussian pulse, and afull width at half maximum (FWHM) of each of the plurality of pulsesranges from 1 ps to 500 ns.

According to another aspect of the inventive concept, there is provideda wafer processing apparatus configured to perform a stealth dicingprocess on a wafer. The wafer processing apparatus may include: a laserapparatus configured to output a laser beam including a plurality ofnon-Gaussian pulses; focusing lens optics configured to focus the laserbeam on an inside of the wafer; and an arbitrary wave generatorconfigured to provide a non-sinusoidal continuous wave power to thelaser apparatus.

According to another aspect of the inventive concept, there is provideda wafer processing apparatus including: a laser apparatus configured togenerate a laser beam; focusing lens optics configured to focus thelaser beam on an inside of a wafer; an arbitrary wave generatorconfigured to supply driving power to the laser apparatus; and acontroller configured to control the arbitrary wave generator, whereinthe laser beam includes a plurality of pulses sequentially emitted fromthe laser apparatus, and wherein a rise time taken for an intensity ofeach of the plurality of pulses to rise from 10% of a peak point to 90%of the peak point of is 1% or more of a full width at half maximum(FWHM) of each of the plurality of pulses and less than 50% of the FWHM.

According to another aspect of the inventive concept, there is provideda method of manufacturing a semiconductor device. The method mayinclude: forming a plurality of semiconductor devices on a wafer;forming an internal breakage on the wafer along a scribe lane defined onthe wafer and being a separation region between the plurality ofsemiconductor devices; and separating the plurality of semiconductordevices, wherein the forming of the internal breakage on the waferincludes: irradiating a laser beam focused inside the wafer, wherein thelaser beam includes a plurality of pulses in which a time interval froma start point to a peak point of each of the plurality of pulses is lessthan a time interval from the peak point to an end point of each of theplurality of pulses.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the inventive concept will be more clearly understoodfrom the following detailed description taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a block diagram illustrating a wafer processing apparatusaccording to embodiments;

FIG. 2 is a schematic diagram illustrating the wafer processingapparatus according to embodiments;

FIG. 3 is a graph illustrating the wafer processing apparatus accordingto embodiments;

FIGS. 4A to 4C are graphs illustrating the effect of a wafer processingapparatus according to embodiments;

FIGS. 5A to 5C are graphs illustrating the effect of a wafer processingapparatus according to embodiments;

FIGS. 6A and 6B are block diagrams illustrating wafer processingapparatuses according to other embodiments;

FIGS. 7A to 10 are diagrams illustrating wafer processing apparatusesaccording to embodiments;

FIG. 11 is a flowchart illustrating a method of manufacturing asemiconductor device in accordance with embodiments; and

FIGS. 12A to 12C are schematic diagrams illustrating a method ofmanufacturing a semiconductor device according to embodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference tothe accompanying drawings. Like numeral references refer to likeelements, and their repetitive descriptions may be omitted in theinterest of brevity.

FIG. 1 is a block diagram illustrating a wafer processing apparatus 100a according to embodiments.

FIG. 2 is a schematic diagram illustrating the wafer processingapparatus 100 a according to embodiments.

FIG. 3 is a graph illustrating the wafer processing apparatus 100 aaccording to embodiments. More specifically, FIG. 3 shows anintensity-time profile of a single pulse output by a laser apparatus 120of FIGS. 1 and 2.

Referring to FIGS. 1 to 3, the wafer processing apparatus 100 a mayinclude an arbitrary wave generator 110, the laser apparatus 120, a beamtransmission optical system 130, focusing lens optics or focusing lensoptical system 140, a controller 150, and a wafer support 160.

The wafer processing apparatus 100 a may perform a stealth dicingprocess. Stealth dicing is a process of separating a wafer on which asemiconductor device is formed at high precision and high speed. Stealthdicing is a technology of focusing a laser beam LB in a wavelength band(that is, a wavelength band having a low absorption rate of the wafer W)that may transmit through the wafer W on a place inside the wafer Wthrough the surface of the wafer W.

In the stealth dicing technology, the laser beam LB may be irradiatedrepeatedly with a pulse that continues for a very short time (e.g., 1 μsor less), and focused on a small region on the wafer W. That is, thelaser beam LB may have spatially (via focusing) and temporally (viapulsing), for example, a high peak power density of about 1×10⁸ [W/cm²]near a focal point set inside the wafer W. The laser beam LB having ahigh peak power density may cause a nonlinear absorption effect withrespect to the wafer W near the focal point, and accordingly, the laserbeam LB transmitting through the surface of the wafer W may be absorbedat a high absorption rate near the focal point inside the wafer W.Therefore, a high density defect (e.g., a dislocation) may occur in apart of the wafer W where the laser beam LB is absorbed, and a verticalbreakage of the wafer W may be facilitated.

The arbitrary wave generator 110 is an apparatus that generates a clocksignal based on an external clock signal, and may include a clockoscillator, a memory address controller, a wave memory, a shiftregister, an analog output circuit, etc.

According to some embodiments, the arbitrary wave generator 110 maygenerate a driving current DI according to a wave generation signal WGSof the controller 150. The arbitrary wave generator 110 may supply thegenerated driving current DI to a main or master oscillator 121.According to some embodiments, the arbitrary wave generator 110 maysupply the driving current DI that is a non-sinusoidal continuous wavesuch that the main oscillator 121 generates a first laser beam LB1 thatcomprises non-Gaussian pulses.

According to some embodiments, the laser apparatus 120 may be a masteroscillator and power amplifier (MOPA) laser apparatus. The laserapparatus 120 may be an optical fiber laser apparatus. The mainoscillator 121, a pre-amplifier 123, and a main amplifier 125 includedin the laser apparatus 120 may be coupled to each other with an opticalfiber. However, the inventive concept is not limited thereto, and thelaser apparatus 120 may be a MOPA laser including a solid bulk laser anda bulk amplifier, or a MOPA laser including a tunable external cavitydiode laser and a semiconductor optical amplifier.

According to some embodiments, the main oscillator 121 may include afiber laser doped with any one of ytterbium (Yb), erbium (Er), thulium(Tm), and holmium (Ho). According to some embodiments, the mainoscillator 121 may generate the first laser beam LB1 having a wavelengthof about 0.8 μm to about 1.4 μm. According to some embodiments, thefirst laser beam LB1, a second laser beam LB2, and the laser beam LB mayhave a wavelength of about 1064 μm.

According to some embodiments, the main oscillator 121 may operate in aQ switching manner. The laser apparatus 120 may generate the first laserbeam LB1 at a pulse frequency of several hundreds of kHz. However, theinventive concept is not limited thereto, and according to someembodiments, the main oscillator 121 may operate in a mode-lockingmanner.

The main oscillator 121 may include a seed laser diode, an optical fiberincluding a gain medium, and first and second mirrors facing each otherto oscillate the first laser beam LB1. The seed laser diode may be adiode that generates a laser by using a forward semiconductor junctionas an active medium. When current is supplied to the seed laser diode,light may be emitted while an inversion occurs between the density of ahigh energy level and the density of a low energy level in thesemiconductor junction.

The light emitted from the seed laser diode may be used as pumpingenergy with respect to the optical fiber including a gain medium. When aplurality of seed laser diodes are provided, a pump-signal couplingapparatus may be intervened or disposed between the plurality of seedlaser diodes and the optical fiber. The pump-signal coupling apparatusmay combine optical signals output from the plurality of seed laserdiodes into one optical signal and transmit the optical signal to theoptical fiber including the gain medium.

Most of light emitted by the spontaneous emission or induced emissionfrom the gain medium of the optical fiber may have a weakdirectionality. The first and second mirrors may reflect the lightemitted from the gain medium back to the gain medium, and thusoscillation in which induced emission of a gain material is repeated mayoccur. Part of the light that is repeatedly reflected between the firstand second mirrors may pass through the second mirror and be output asthe first laser beam LB1. The first laser beam LB1 may be coherentlight.

The main oscillator 121 may further include an optical modulator foradjusting the intensity-time profile of the first laser beam LB1. Theoptical modulator may include an aperture capable of transmitting orshielding the first laser beam LB1, and adjust the intensity-timeprofile of the first laser beam LB1 by adjusting the transmittance ofthe first laser beam LB1 transmitting the aperture.

The pre-amplifier 123 may include a first pump laser diode, and the mainamplifier 125 may include a second pump laser diode. According to someembodiments, a plurality of first pump laser diodes included in thepre-amplifier 123 may be provided. According to some embodiments, aplurality of second pump laser diodes included in the main amplifier 125may be provided.

The pre-amplifier 123 may amplify the first laser beam LB1 to output thesecond laser beam LB2. The second laser beam LB2 may have the samewavelength as the first laser beam LB1. The main amplifier 125 mayamplify the second laser beam LB2 to output the laser beam LB. The laserbeam LB may have the same wavelength as the second laser beam LB2.

The first laser beam LB1, the second laser beam LB2, and the laser beamLB may have the same intensity-time profile by adjusting anamplification ratio. For example, the first laser beam LB1, the secondlaser beam LB2, and the laser beam LB may have substantially the samepulse width, kurtosis, and skewness. However, the inventive concept isnot limited thereto, and any one of the first and second laser beams LB1and LB2 may have a different pulse width, kurtosis, and skewness thanthe laser beam LB.

The first pump laser diode included in the pre-amplifier 123 maygenerate a first pump laser beam. The second pump laser diode includedin the main amplifier 125 may generate a second pump laser beam. Thefirst pump laser beam may join an optical path of the first laser beamLB1 by an optical coupler, and the second pump laser beam may join anoptical path of the second laser beam LB2 by the optical coupler. Thefirst and second pump laser diodes may be driven by radio frequency (RF)power.

According to some embodiments, the first and second pump laser beams mayhave different wavelengths from the first laser beam LB1. According tosome embodiments, the first and second pump laser beams may have shorterwavelengths than the first laser beam LB1. According to someembodiments, the first and second pump laser beams may have wavelengthshaving a higher absorption rate with respect to the optical fiber thanthe laser beam LB. As the first pump laser beam is absorbed by theoptical fiber, the first laser beam LB1 may be amplified and the secondlaser beam LB2 may be output. As the second pump laser beam is absorbedby the optical fiber, the second laser beam LB2 may be amplified and thelaser beam LB may be output. However, the inventive concept is notlimited thereto, and the first and second pump laser beams may have thesame wavelength as the first laser beam LB1.

According to some embodiments, an isolator may be provided each betweenthe main oscillator 121 and the pre-amplifier 123 and between thepre-amplifier 123 and the main amplifier 125. The isolator may be alsoreferred to as an optical diode, and is an optical component that allowslight to be transmitted in only one direction. The isolator may preventreverse propagation of the first laser beam LB1 and the second laserbeam LB2.

According to some embodiments, an additional pre-amplifier may befurther provided between the pre-amplifier 123 and the main amplifier125 depending on the intensity of the laser beam LB that is finallyoutput from the laser apparatus 120. For example, the laser apparatus120 may include two or more pre-amplifiers. The isolator and acollimator may be provided in an output terminal where the laser beam LBis output from the laser apparatus 120.

According to some embodiments, the intensity-time profile (hereinafter,a time profile) of the single pulse (hereinafter simply, a single pulse)included in the first laser beam LB1, the second laser beam LB2, and thelaser beam LB may differ from the Gaussian distribution. According tosome embodiments, the time profile of the single pulse may be differentfrom the Laurentian distribution.

According to some embodiments, the full width at half maximum (FWHM) ofthe single pulse may range from about 1 ps to about 1 μs. According tosome embodiments, the FWHM of the single pulse may be about 500 ns orless. According to some embodiments, the FWHM of the single pulse may beabout 400 ns or less. According to some embodiments, the FWHM of thesingle pulse may be about 300 ns or less.

According to some embodiments, the time profile of the single pulse maybe asymmetric with respect to the center of the pulse. Here, the centerof the pulse means a midpoint of the start and end points of the pulse(e.g., a point where t=0 in FIG. 3). According to some embodiments, thetime interval from a start point SP of the single pulse to a peak pointPP of the intensity may be less than the time interval from the peakpoint PP of the intensity to an end point EP of the single pulse.

According to some embodiments, a rise time may be about 1% or more andless than about 50% of the FWHM of the single pulse. Here, the rise timemeans a time taken for the intensity of the single pulse to increasefrom 10% of the peak point PP to 90% of the peak point PP. According tosome embodiments, the rise time may be less than or equal to about 40%of the FWHM. According to some embodiments, the rise time may be about30% or less of the FWHM. According to some embodiments, the rise timemay be about 20% or less of the FWHM. According to some embodiments, therise time may be about 10% or less of the FWHM.

According to some embodiments, the peak power of the single pulse mayrange from about 1 W to about 1 kW.

According to some embodiments, the average power of the single pulse mayrange from about 1 W to about 30 W.

According to some embodiments, the time profile of the single pulse mayfollow Equation 1 below.

$\begin{matrix}{{I(t)} = {E\;\frac{\beta}{2\;{\alpha \cdot {\Gamma\left( \frac{1}{\beta} \right)}}}{{\exp\left\lbrack {- \left( \frac{t - \mu}{\alpha} \right)^{\beta}} \right\rbrack}\left\lbrack {1 + {{erf}\left( {\frac{s}{\sqrt{2}} \cdot \frac{t - \mu}{\alpha}} \right)}} \right\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

Here, E denotes an energy parameter for controlling the energy amount ofthe pulse, α denotes a pulse width parameter for controlling the pulsewidth of the pulse, β denotes a kurtosis parameter for controllingkurtosis of the pulse, and s denotes a skewness parameter forcontrolling skewness of the pulse. In addition, μ denotes a parameterfor controlling the time axis parallel movement of the pulse, and may beautomatically determined by the other parameters E, α, β, and s.

In addition, in Equation 1, the gamma function Γ(z)and the Gaussianerror function erf(x) follow Equation 2 below.

$\begin{matrix}{{{\Gamma(z)} = {\int_{0}^{\infty}{x^{z - 1}e^{- x}{dx}}}}{{{erf}(x)} = {\frac{2}{\pi}{\int_{0}^{x}{e^{- t^{2}}{dt}}}}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

When the single pulse follows a Gaussian profile, β may be 2 and s mayhave a value of 0. According to embodiments, the skewness parameter s ofthe pulse may have a non-zero value. According to some embodiments, theskewness parameter s of the single pulse may be greater than zero.According to some embodiments, the skewness parameter s of the singlepulse may be about 5 or more. According to some embodiments, theskewness parameter s of the single pulse may be about 10 or more.According to some embodiments, the skewness parameter s of the singlepulse may be about 100 or less. According to some embodiments, theskewness parameter s of the single pulse may be about 60 or less.

Stealth laser apparatuses according to the related art have performed astealth dicing process using a laser pulse conforming to the Gaussianprofile. However, there is a problem in that depending on the conditionsof the stealth laser apparatus and the characteristics of the wafer W onwhich the process is performed, including that a chip defect occurs in adicing process because breakage formed inside the wafer W is nottransferred to the surface of the wafer W. There is a problem in thatthe defect occurring in the dicing process causes permanent damage tothe semiconductor chip close to a completion stage, which increasesmanufacturing cost and decreases yield. In particular, there is aproblem in that when the power (e.g., peak power, or average power) ofthe laser beam increases to enhance individualization performance of thestealth dicing laser, the completed semiconductor devices may be damagedby the laser beam, which deteriorates the yield.

According to embodiments, each of the single pulses constituting thelaser beam LB generated by the laser apparatus 120 may have a relativelyshort rise time, unlike the Gaussian pulse. As will be described below,it has been confirmed that the laser beam LB of a pulse train having ashort rise time rapidly increases the temperature near a processingpoint (i.e., the focus of the laser beam LB) of the wafer W. As aresult, the ratio of energy absorbed by a part of the energy of thesingle pulse near the focal point in the wafer W increases, and thus,breakage may be formed inside the wafer W more effectively. Accordingly,the reliability of the stealth dicing process may be improved.Furthermore, while the power of the laser beam LB is maintained withinthe range that does not damage the semiconductor device, the divisionperformance may be improved, and thus, the yield of semiconductor devicemanufacturing may be improved.

The output laser beam LB may be transferred to the focusing lens optics140 by the beam transmission optical system 130. The beam transmissionoptical system 130 may be or include free space optics, but is notlimited thereto. The beam transmission optical system 130 may includevarious optical elements such as a polarizer, a lens, a reflector, aprism, a splitter, etc.

The focusing lens optics 140 may focus the laser beam LB on a positionset inside the wafer W. The focusing lens optics 140 may include asingle lens or may include a plurality of lenses.

The wafer support 160 may support the wafer W while the wafer W is beingprocessed. The wafer support 160 may move the wafer W in a horizontaldirection such that the laser beam LB is focused on different partsinside the wafer W. Accordingly, the wafer W may be scanned along ascribe lane SL (see, e.g., FIG. 12A) defined in the wafer W, andbreakages may be formed in different parts inside the wafer W.

According to embodiments, the controller 150 may generate a wavegeneration signal WGS for controlling the arbitrary wave generator 110.The wave generation signal WGS may include bits with respect to a timeprofile of the driving current DI.

The bit with respect to the time profile of the driving current DIincluded in the wave generation signal WGS may include, based on thetime profile of the driving current DI, i) a bit (hereinafter, anaverage power control bit) for controlling the average power of thesingle pulse constituting the first laser beam LB1, ii) a bit(hereinafter, a pulse width control bit) for controlling pulse width ofthe single pulse constituting the first laser beam LB1, iii) a bit(hereinafter, a kurtosis control bit) for controlling the kurtosis ofthe single pulse constituting the first laser beam LB1, and iv) a bit(hereinafter, a skewness control bit) for controlling the skewness ofthe single pulse constituting the first laser beam LB1.

The stealth dicing lasers according to the related art generate aGaussian laser beam pulse by supplying RF power to a main oscillator andoperating the main oscillator in a Q switching manner. According toembodiments, to generate the first laser beam LB1 having thenon-Gaussian profile, the wave generation signal WGS may include theaverage power control bit, the pulse width control bit, the kurtosiscontrol bit, and the skewness control bit.

Here, the controller 150 may be implemented with hardware, firmware,software, or an arbitrary combination thereof. For example, thecontroller 150 may be a computing device such as a workstation computer,a desktop computer, a laptop computer, or a tablet computer. Thecontroller 150 may be a simple controller, a microprocessor, a centralprocessing unit (CPU), a complicated processor such as a graphicsprocessing unit (GPU), a processor configured with software, dedicatedhardware, or dedicated firmware. The controller 150 may be implementedwith a general-use computer or application specific hardware such as adigital signal processor (DSP), a field programmable gate array (FPGA),or an application specific integrated circuit (ASIC).

According to some embodiments, an operation of the controller 150 may beimplemented as instructions stored in a machine-readable medium capableof being read and executed by one or more processors. In this regard,the machine-readable medium may include an arbitrary mechanism forstoring and/or transmitting information readable by a machine (forexample, a computing device). For example, the machine-readable mediummay include read-only memory (ROM), random access memory (RAM), amagnetic disk storage medium, an optical storage medium, a flash memorydevice, an electrical, optical, acoustic, or other-type radio signal(for example, a carrier, an infrared signal, a digital signal, or thelike), and other arbitrary signals.

In addition, firmware, software, routines, and instructions forperforming the operations described with respect to the controller 150or an arbitrary process described below may be so configured. Forexample, the controller 150 may be implemented with software thatgenerates a signal for controlling the arbitrary wave generator 110.However, for convenience of description, the operation of the controller150 described above may be based on a computing device, a processor, acontroller, or another device for executing firmware, software,routines, instructions, etc.

FIGS. 4A to 4C are graphs illustrating the effect of the waferprocessing apparatus 100 a according to embodiments.

Referring to FIGS. 4A to 4C, thick solid lines indicate the intensity ofa single pulse of the laser beam LB (see FIG. 1) over time, and thinsolid lines indicate the absorption power of the wafer W (see FIG. 1).

The pulse of FIG. 4A is a leading pulse in which the peak of the pulseis leading the center of the pulse, the pulse of FIG. 4B is the Gaussianpulse of which the peak of the pulse is substantially the same as thecenter of the pulse, and the pulse of FIG. 4C is a lagging pulse inwhich the peak of the pulse is lagging the center of the pulse.

Referring to FIGS. 2 and 4A, it is confirmed with the leading pulse thatthe absorption power of the wafer W rapidly increases, and the wafer Wabsorbed 92.4% of the energy of the pulse of the laser beam LB.

Referring to FIGS. 2 and 4B, it is confirmed with the Gaussian pulsethat the wafer W absorbed 84.6% of the energy of the pulse of the laserbeam LB.

Referring to FIGS. 2 and 4C, it is confirmed with the lagging pulse thatthe rise in the absorption power of the wafer W is delayed, and thewafer W absorbs 77.6% of the energy of the pulse of the laser beam LB.

The wafer processing apparatus 100 a according to embodiments mayperform a stealth dicing process using the leading pulse, and thus, theabsorption rate of the laser beam LB may increase. Accordingly, aninternal breakage IB (see, e.g., FIG. 12C) of the wafer W mayeffectively propagate to the surface of the wafer W, and the reliabilityof the stealth dicing process and the semiconductor device manufacturingyield may be improved.

In addition, as the absorption rate of the laser beam LB increases, thesemiconductor device formed in the wafer W may be prevented from beingdamaged by the leakage beam, and the yield and reliability ofsemiconductor device manufacturing may be improved.

FIGS. 5A to 5C are graphs illustrating the effect of the waferprocessing apparatus 100 a according to embodiments.

More specifically, FIG. 5A shows the temperature change inside the wafer(W, see FIG. 1) in a stealth dicing process using the laser beam (LB,see FIG. 1) including the Gaussian pulse, FIG. 5B shows the temperaturechange inside the wafer (W, see FIG. 1) in the stealth dicing processusing the laser beam (LB, see FIG. 1) including the leading pulse, andFIG. 5C shows the temperature change inside the wafer (W, see FIG. 1) inthe stealth dicing process using the laser beam (LB, see FIG. 1)including the lagging pulse.

In FIGS. 5A to 5C, the vertical depth refers to a depth in a directionperpendicular to the surface of the wafer (W, see FIG. 1) from thesurface of the wafer (W, see FIG. 1) on which the laser beam (LB, seeFIG. 1) is incident. The focus of the laser beam (LB, see FIG. 1) is ata point where the vertical depth is 100 μm. In FIGS. 5A to 5C, solidlines indicate the temperature change at a point where the verticaldepth is 95 μm, broken lines indicate the temperature change at a pointwhere the vertical depth is 85 μm, and dashed-dotted lines indicate thetemperature change at a point where the vertical depth is 75 μm.

Referring to FIG. 5A, in the stealth dicing process using the Gaussianpulse, the energy of the pulse propagates well to the point where thevertical depth is 85 μm, and the temperature rises to 2000 K, while theenergy of the pulse does not propagate well to the point where thevertical depth is 75 μm, the temperature rises to only about 1000K, andthe vertical length of the internal breakage IB is about 50 μm.

Referring to FIG. 5B, in the stealth dicing process using the leadingpulse, the energy of the pulse propagates well to the point where thevertical depth is 75 μm and the temperature rises to 2000K. Because theabsorption rate of light in a near-infrared band is proportional to thetemperature of the wafer (i.e., silicon), the faster the temperature ofthe wafer (W, see FIG. 1) rises, the faster the absorption rate of thepulses rises, and thus, the ratio of energy lost in the pulse energy maybe reduced. It is confirmed that in the case of using the leading pulse,the vertical length of the internal breakage IB is about 61 μm andincreases about 21% compared to the case of using the Gaussian pulse.

Referring to FIG. 5C, it is confirmed in the lagging pulse that theenergy hardly propagates to the point where the vertical depth is 75 μm,the temperature rise is insignificant and the internal breakage IB isreduced by about 20%.

The wafer processing apparatus 100 a (see FIG. 1) according toembodiments has improved internal breakage formation performance.Accordingly, the distance between the internal breakage IB formed in thewafer W may increase compared to the related art, and the number offormations of vertically overlapped internal breakages on the same pointmay be reduced, and thus, the scanning speed of the stealth dicingprocess may be improved. Accordingly, the productivity of semiconductordevice manufacturing may be improved.

FIGS. 6A and 6B are block diagrams illustrating wafer processingapparatuses 100 b and 100 c respectively according to other embodiments.

For convenience of description, description which is redundant with thedescription given above with reference to FIGS. 1 to 3 may be omitted,and a difference will be mainly described.

Referring to FIG. 6A, the wafer processing apparatus 100 b may includethe arbitrary wave generator 110, the laser apparatus 120, the beamtransmission optical system 130, the focusing lens optics 140, thecontroller 150, and the wafer support 160.

In the wafer processing apparatus 100 b, unlike the wafer processingapparatus 100 a of FIG. 1, the main or master oscillator 121 may operatebased on RF power. Accordingly, the first laser beam LB1 may be theGaussian pulse.

According to some embodiments, the pre-amplifier 123 may operate basedon the driving current DI that is a non-sinusoidal continuous wave.Accordingly, the pre-amplifier 123 may generate the second laser beamLB2 that is a non-Gaussian pulse based on the first laser beam LB1 thatis the Gaussian pulse.

The characteristics of the second laser beam LB2 and the laser beam LBare similar to those described with reference to FIGS. 1 to 3.

Referring to FIG. 6B, the wafer processing apparatus 100 c may includethe arbitrary wave generator 110, the laser apparatus 120, the beamtransmission optical system 130, the focusing lens optics 140, thecontroller 150, and the wafer support 160.

Unlike the wafer processing apparatus 100 a of FIG. 1, the waferprocessing apparatus 100 b may include the main oscillator 121 driven byRF power. Accordingly, the first laser beam LB1 may be the Gaussianpulse.

According to some embodiments, the pre-amplifier 123 may be driven by RFpower. Accordingly, the pre-amplifier 123 may generate the second laserbeam LB2 that is the Gaussian pulse of larger amplitude based on thefirst laser beam LB1 that is the Gaussian pulse.

According to some embodiments, the main amplifier 125 may operate basedon the driving current DI that is a non-sinusoidal continuous wave.Accordingly, the main amplifier 125 may generate the laser beam LB thatis a non-Gaussian pulse based on the second laser beam LB2 that is theGaussian pulse.

FIG. 7A is a diagram illustrating a wafer processing apparatus 200 aaccording to embodiments.

For convenience of description, description which is the redundant withthe description given above with reference to FIGS. 1 to 3 may beomitted, and a difference will be mainly described.

Referring to FIG. 7A, the wafer processing apparatus 200 a may furtherinclude a sensor 170 in addition to the arbitrary wave generator 110,the laser apparatus 120, the beam transmission optical system 130, thefocusing lens optics 140, the controller 150, and the wafer support 160.

The sensor 170 may be coupled to the main oscillator 121 by an opticalfiber. The sensor 170 may receive part of the first laser beam LB1through the optical fiber and generate an electrical signal based on thepart of the first laser beam LB1.

The controller 150 may determine whether the profile of a single pulseincluded in the first laser beam LB1 follows a set profile based on theelectrical signal of the sensor 170. The controller 150 may provide thecorrected wave generation signal WGS to the arbitrary wave generator 110based on a measurement result of the sensor 170. For example, when it isdetermined that the first laser beam LB1 is the Gaussian pulse from thesensor 170, the controller 150 may provide the corrected wave generationsignal WGS for correcting the first laser beam LB1 with the presetprofile, for example, a non-Gaussian pulse, to the arbitrary wavegenerator 110. According to some embodiments, a separate processor thatgenerates a feedback signal based on the measurement result of thesensor 170 and provides the feedback signal to the controller 150 may befurther provided.

FIG. 7B is a diagram illustrating a wafer processing apparatus 200 baccording to embodiments.

For convenience of description, description which is redundant with thedescription given above with reference to FIG. 7A may be omitted, and adifference will be mainly described.

Referring to FIG. 7B, the wafer processing apparatus 200 b may includethe arbitrary wave generator 110, the laser apparatus 120, the beamtransmission optical system 130, the focusing lens optics 140, thecontroller 150, the wafer support 160, and the sensor 170.

Referring to FIG. 7B, the sensor 170 included in the wafer processingapparatus 200 b may transmit an electrical signal to the arbitrary wavegenerator 110 unlike in FIG. 7A.

The arbitrary wave generator 110 may adjust the driving current DI basedon the wave generation signal WGS of the controller 150 and ameasurement result of the sensor 170, and thus, the main oscillator 121may output the laser beam LB having a set wave time profile.

FIG. 7C is a diagram illustrating a wafer processing apparatus 200 caccording to embodiments.

For convenience of description, description which is redundant with thedescription given above with reference to FIG. 7A may be omitted, and adifference will be mainly described.

Referring to FIG. 7C, the wafer processing apparatus 200 c may includethe arbitrary wave generator 110, the laser apparatus 120, the beamtransmission optical system 130, the focusing lens optics 140, thecontroller 150, the wafer support 160, and the sensor 170.

Referring to FIG. 7C, the sensor 170 included in the wafer processingapparatus 200 c may be coupled to the pre-amplifier 123 through anoptical fiber to sense a part of the second laser beam LB2, unlike inFIG. 7A.

FIG. 7D is a diagram illustrating a wafer processing apparatus 200 daccording to embodiments.

For convenience of description, description which is redundant with thedescription given above with reference to FIG. 7A may be omitted, and adifference will be mainly described.

Referring to FIG. 7D, the wafer processing apparatus 200 d may includethe arbitrary wave generator 110, the laser apparatus 120, the beamtransmission optical system 130, the focusing lens optics 140, thecontroller 150, the wafer support 160, and the sensor 170.

Referring to FIG. 7D, the sensor 170 included in the wafer processingapparatus 200 d may be coupled to the main amplifier 125 through anoptical fiber to sense a part of the laser beam LB, unlike in FIG. 7A.

FIG. 7E is a diagram illustrating a wafer processing apparatus 200 eaccording to embodiments.

For convenience of description, description which is redundant with thedescription given above with reference to FIG. 7A may be omitted, and adifference will be mainly described.

Referring to FIG. 7E, the wafer processing apparatus 200 e may includethe arbitrary wave generator 110, the laser apparatus 120, the beamtransmission optical system 130, the focusing lens optics 140, thecontroller 150, the wafer support 160, a beam splitter 191, and a sensor195.

A part of the laser beam LB that has transmitted through the beamsplitter 191 may be focused on the inside of the wafer W through thebeam transmission optical system 130 and the focusing lens optics 140.

A part of the laser beam LB reflected by the beam splitter 191 may besensed by the sensor 195.

FIG. 8 is a diagram illustrating a wafer processing apparatus 300according to embodiments.

For convenience of description, description which is redundant with thedescription given above with reference to FIGS. 1 to 3 may be omitted,and a difference will be mainly described.

Referring to FIG. 8, the wafer processing apparatus 300 may include alaser apparatus 320, the beam transmission optical system 130, thefocusing lens optics 140, the controller 150, and the wafer support 160.

Unlike the laser apparatus 120 of FIG. 1, the laser apparatus 320 mayinclude the arbitrary wave generator 110. The arbitrary wave generator110 is substantially the same as described with reference to FIG. 1,except that the arbitrary wave generator 110 is embedded in the laserapparatus 320.

FIG. 9 is a diagram illustrating a wafer processing apparatus 400according to embodiments.

For convenience of description, description which is redundant with thedescription given above with reference to FIGS. 1 to 3 may be omitted,and a difference will be mainly described.

Referring to FIG. 9, the wafer processing apparatus 400 may include anarbitrary wave generator 110′, the laser apparatus 120, the beamtransmission optical system 130, the focusing lens optics 140, thecontroller 150, the wafer support 160, an RF amplifier 181 and a voltagesupply 185.

Unlike the arbitrary wave generator 110 of FIG. 1, the arbitrary wavegenerator 110′ of FIG. 9 may supply an arbitrary wave voltage AWV, whichis a non-sinusoidal continuous wave voltage, to the RF amplifier 181.The RF amplifier 181 may amplify the arbitrary wave voltage AWV tosupply a driving voltage DV to the main oscillator 121. The arbitrarywave voltage AWV may have the same wave as the driving voltage DV byamplification of the amplitude.

The voltage supply 185 may provide the main oscillator 121 with avoltage bias smaller than a threshold voltage value and having aconstant magnitude. Accordingly, the leakage of power provided by the RFamplifier 181 may be prevented, and the pulse peak power performance ofthe main oscillator 121 may be guaranteed or improved.

FIG. 10 is a diagram illustrating a wafer processing apparatus 500according to embodiments.

For convenience of description, description previously given withreference to FIGS. 1 to 3 may be omitted and differences are mainlydescribed.

Referring to FIG. 10, the wafer processing apparatus 500 may include thearbitrary wave generator 110, a single oscillator laser 510, the beamtransmission optical system 130, the focusing lens optics 140, thecontroller 150, and the wafer support 160.

Unlike the wafer processing apparatus 100 a of FIG. 1, the waferprocessing apparatus 500 of FIG. 10 may include the single oscillatorlaser 510. The single oscillator laser 510 may output the laser beam LBhaving a time profile that is substantially the same as that describedwith reference to FIG. 3 based on the driving current DI of thearbitrary wave generator 110.

FIG. 11 is a flowchart illustrating a method of manufacturing asemiconductor device in accordance with embodiments.

FIGS. 12A to 12C are schematic diagrams illustrating a method ofmanufacturing a semiconductor device according to embodiments.

Referring to FIGS. 11 and 12A, in P10, the semiconductor device may beformed on the wafer W. The wafer W may include device formation regionsin which semiconductor devices are formed, and scribe lanes SLseparating the device formation regions.

The wafer W may include, for example, silicon (Si). The wafer W mayinclude a semiconductor element, such as germanium (Ge), or a compoundsemiconductor such as silicon carbide (SiC), gallium arsenide (GaAs),indium arsenide (InAs), or indium phosphide (InP).

According to some embodiments, the wafer W may have a silicon oninsulator (SOI) structure. The wafer W may include a buried oxide layerformed on the front surface of the wafer W. According to someembodiments, the wafer W may include a conductive region (for example,an impurity-doped well) formed in the front surface of the wafer W.According to some embodiments, the wafer W may have various isolationstructures such as a shallow trench isolation (STI) isolating theimpurity-doped well. Although not shown, a plurality of material layersmay be formed in the front surface of the wafer W. At least one materiallayer may be formed in the back surface of the wafer W.

The semiconductor device formed in the wafer W may be any one of amemory device and a non-memory device. According to some embodiments,the memory device may include a non-volatile NAND flash memory.According to some embodiments, the memory device may include phasechange random access memory (PRAM), magnetic random access memory(MRAM), resistance random access memory (ReRAM), ferroelectric randomaccess memory (FRAM), NOR flash memory, etc. Also, the memory device maybe a volatile memory device where data is lost when power is cut off,like dynamic random access memory (DRAM) and static random access memory(SRAM). According to some embodiments, the memory device may be a logicchip, a measurement device, a communication device, a digital signalprocessor (DSP), or a system-on-chip (SoC).

A process of forming the semiconductor device may include: i) anoxidation process of forming an oxide film, ii) a lithography processincluding spin coating, exposure and development, iii) a thin filmdeposition process, iv) a dry or wet etching process, and v) a metalwiring process.

The oxidation process is a process of chemically reacting oxygen orwater vapor with a silicon substrate surface at a high temperature of800 to 1200 degrees to form a thin and uniform silicon oxide film. Theoxidation process may include dry oxidation and wet oxidation. Dryoxidation may react the wafer W with oxygen gas to form an oxide film.Wet oxidation may react the wafer W with oxygen and water vapor to forman oxide film.

According to some embodiments, an SOI structure may be formed on asubstrate by the oxidation process. The substrate may also include aburied oxide layer. According to some embodiments, the substrate mayhave various device isolation structures such as STI.

The lithography process is a process of transferring a circuit patternpreviously formed on a lithography mask to the substrate throughexposure. The lithography process may be performed in the order of spincoating, exposure and development process.

The thin film deposition process may include any one of, for example,atomic layer deposition (ALD), chemical vapor deposition (CVD),plasma-enhanced CVD (PECVD), metal organic CVD (MOCVD), physical vapordeposition (PVD), reactive pulsed laser deposition, molecular beamepitaxy and DC magnetron sputtering.

The dry etching process may include any one of, for example, reactiveion etching (RIE), deep RIE (DRIE), ion beam etching (IBE), and Armilling. As another example, the dry etching process that may beperformed on the wafer W may be Atomic Layer Etching (ALE). In addition,the wet etching process that may be performed on the wafer W may includean etching process that uses at least one of Cl₂, HCl, CHF₃, CH₂F₂,CH₃F, H₂, BCL₃, SiCl₄, Br₂, HBr, NF₃, CF₄, C₂F₆, C₄F₈, SF₆, O₂, SO₂, andCOS as an etchant gas.

The metal wiring process may be a process of forming a conductive wiring(metal line) to implement a circuit pattern for operation of thesemiconductor device. By the metal wiring process, transmission paths ofground, power, and signal for operating the semiconductor device may beformed. The metal wiring may include gold, platinum, silver, aluminum,and tungsten.

According to some embodiments, in the process of forming thesemiconductor device, a planarization process, such as a chemicalmechanical polishing (CMP) process, an ion implantation process, etc.,may also be performed.

Referring to FIGS. 11 and 12B, in P20, the internal breakage IB may beformed in the wafer W.

The internal breakage IB of the wafer W may be formed by the laser beamLB output by any one of the wafer processing apparatus 100 a of FIG. 1and the wafer processing apparatuses 100 b, 100 c, 200 a, 200 b, 200 c,200 d, 200 e, 300, 400, and 500 of FIGS. 6A to 10 respectively.

According to some embodiments, to reduce the thickness of the wafer Wbefore the formation of the internal breakage IB in the wafer W, apre-grinding process on the back surface of the wafer W (i.e., a surfaceopposite to the front surface of the wafer W on which the semiconductordevice is formed) may be performed.

Referring to FIGS. 11 and 12C, in P30, the semiconductor device may beseparated.

After attaching the wafer W on which the internal breakage IB is formedto a die attach film DAF, the semiconductor device may be separated bystretching the die attach film DAF in the horizontal direction.

According to some embodiments, before providing the die attach film DAF,a back-grinding process of polishing the back surface of the wafer W maybe additionally performed.

Referring to FIG. 11, in P40, the separated semiconductor devices may bepackaged.

The packaging process may include a wire bonding process, a moldingprocess, a marking process, a solder ball mounting process, etc.

While the inventive concept has been particularly shown and describedwith reference to embodiments thereof, it will be understood thatvarious changes in form and details may be made therein withoutdeparting from the scope of the following claims.

1. A wafer processing apparatus comprising: a laser apparatus configuredto generate a laser beam; a focusing lens optical system configured tofocus the laser beam on an inside of a wafer; an arbitrary wavegenerator configured to supply driving power to the laser apparatus; anda controller configured to control the arbitrary wave generator, whereinthe laser beam comprises a plurality of pulses sequentially emitted fromthe laser apparatus, and wherein each of the plurality of pulses is anon-Gaussian pulse, and a full width at half maximum (FWHM) of each ofthe plurality of pulses ranges from 1 ps to 500 ns.
 2. The waferprocessing apparatus of claim 1, wherein a time interval from a startpoint to a peak point of each of the plurality of pulses is less than atime interval from the peak point to an end point of the plurality ofpulses.
 3. The wafer processing apparatus of claim 1, wherein a risetime taken for an intensity of each of the plurality of pulses to risefrom 10% of a peak point to 90% of the peak point is 1% or more of theFWHM and less than 50% of the FWHM.
 4. The wafer processing apparatus ofclaim 3, wherein the rise time is 30% or less of the FWHM.
 5. The waferprocessing apparatus of claim 3, wherein the rise time is 10% or less ofthe FWHM.
 6. The wafer processing apparatus of claim 1, wherein thelaser apparatus comprises: a main oscillator configured to output afirst laser beam; a pre-amplifier configured to amplify the first laserbeam and output a second laser beam; and a main amplifier configured toamplify the second laser beam and output the laser beam.
 7. The waferprocessing apparatus of claim 6, further comprising a sensor coupled tothe main oscillator and configured to measure an intensity-time profileof the first laser beam and to provide the intensity-time profile to thecontroller.
 8. The wafer processing apparatus of claim 6, furthercomprising a sensor coupled to the pre-amplifier and configured tomeasure an intensity-time profile of the second laser beam and toprovide the intensity-time profile to the controller.
 9. The waferprocessing apparatus of claim 6, further comprising a sensor coupled tothe main amplifier and configured to measure an intensity-time profileof the laser beam and to provide the intensity-time profile to thecontroller.
 10. A wafer processing apparatus configured to perform astealth dicing process on a wafer, the wafer processing apparatuscomprising: a laser apparatus configured to output a laser beamcomprising a plurality of non-Gaussian pulses; focusing lens opticsconfigured to focus the laser beam on an inside of the wafer; and anarbitrary wave generator configured to provide non-sinusoidal continuouswave power to the laser apparatus.
 11. The wafer processing apparatus ofclaim 10, wherein the laser apparatus comprises: a main oscillatorconfigured to output a first laser beam; a pre-amplifier configured toamplify the first laser beam and output a second laser beam; and a mainamplifier configured to amplify the second laser beam and output thelaser beam.
 12. The wafer processing apparatus of claim 11, wherein thearbitrary wave generator is configured to supply non-sinusoidalcontinuous wave power to the main oscillator, the pre-amplifier and themain amplifier are driven by radio frequency (RF) sinusoidal power, andthe first laser beam comprises a plurality of non-Gaussian pulses. 13.The wafer processing apparatus of claim 11, wherein the arbitrary wavegenerator is configured to supply non-sinusoidal continuous wave powerto the pre-amplifier, the main oscillator and the main amplifier aredriven by RF sinusoidal power, the first laser beam comprises aplurality of Gaussian pulses, and the second laser beam comprises aplurality of non-Gaussian pulses.
 14. The wafer processing apparatus ofclaim 11, wherein the arbitrary wave generator is configured to supplynon-sinusoidal continuous wave power to the main amplifier, the mainoscillator and the pre-amplifier are driven by RF sinusoidal power, andeach of the first and second laser beams comprises a plurality ofGaussian pulses.
 15. A wafer processing apparatus comprising: a laserapparatus configured to generate a laser beam; focusing lens opticsconfigured to focus the laser beam on an inside of a wafer; an arbitrarywave generator configured to supply driving power to the laserapparatus; and a controller configured to control the arbitrary wavegenerator, wherein the laser beam comprises a plurality of pulsessequentially emitted from the laser apparatus, and wherein a rise timetaken for an intensity of each of the plurality of pulses to rise from10% of a peak point to 90% of the peak point is 1% or more of a fullwidth at half maximum (FWHM) of each of the plurality of pulses and lessthan 50% of the FWHM.
 16. The wafer processing apparatus of claim 15,wherein an intensity-time profile of each of the plurality of pulsesfollows Equation 1 below, $\begin{matrix}{{I(t)} = {E\;\frac{\beta}{2\;{\alpha \cdot {\Gamma\left( \frac{1}{\beta} \right)}}}{{\exp\left\lbrack {- \left( \frac{t - \mu}{\alpha} \right)^{\beta}} \right\rbrack}\left\lbrack {1 + {{erf}\left( {\frac{s}{\sqrt{2}} \cdot \frac{t - \mu}{\alpha}} \right)}} \right\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$ wherein E denotes an energy parameter for controlling anenergy amount of each of the plurality of pulses, α denotes a pulsewidth parameter for controlling a pulse width of each of the pluralityof pulses, β denotes a kurtosis parameter for controlling kurtosis ofeach of the plurality of pulses, s denotes a skewness parameter forcontrolling skewness of each of the plurality of pulses,μ denotes aparameter for controlling a time axis parallel movement of each of theplurality of pulses, and a gamma function Γ(z)and a Gaussian errorfunction erf(x) follow Equation 2 below, and $\begin{matrix}{{{\Gamma(z)} = {\int_{0}^{\infty}{x^{z - 1}e^{- x}{dx}}}}{{{erf}(x)} = {\frac{2}{\pi}{\int_{0}^{x}{e^{- t^{2}}{dt}}}}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$ the skewness parameter s is greater than 0 and 100 orless.
 17. The wafer processing apparatus of claim 16, wherein theskewness parameter s is 10 or more.
 18. The wafer processing apparatusof claim 16, wherein the controller is configured to generate a wavegeneration signal for controlling the arbitrary wave generator, andwherein the wave generation signal comprises a bit for controlling theskewness parameters.
 19. The wafer processing apparatus of claim 16,wherein the wave generation signal comprises a bit for controlling thekurtosis parameter β.
 20. The wafer processing apparatus of claim 15,wherein the rise time is 30% or less of the FWHM. 21-24. (canceled)